Locking device for pivotally opposed members



Feb. 8, 1955 c. H. ORTMAN LOCKING DEVICE FOR PIVOTALLY OPPOSED MEMBERS Filed April 50, 1955 INVEN TOR. CYARLES 16 Germ/w lrroems'y United States Patent LOCKING DEVICE FOR PIVOTALLY OPPOSED MEMBERS Charles H. Ortman, Chardon, Ohio, assignor of one-third to Ira J. Warner, Cleveland, Ohio Application April 30, 1953, Serial No. 352,115

Claims. (Cl. 81-49) My invention relates to locking or clamping means for handles, levers and similar elements, and relates more particularly to means whereby levers or handles may be locked in any one of a plurality of predetermined positions. The invention is equally well applicable to handles, levers or clamping elements which may be opposed or crossed with respect to each other.

It is one of the objects of my invention to provide an effective clamping device for levers, handles or similar elements whereby the same may be releasably locked in any predetermined position without the use of springs or other resilient members.

A further object of the invention is to provide a device of this kind which is extremely simple in construction and which, being simple of construction, is inexpensive to manufacture.

A further object of the invention is a clamping device for levers, handles and the like which is positive in operation.

A still further object of the invention is the provision of a simple locking means for members suchas handles, levers or the like in which there is provided but one part movable relative to said levers or handles.

Another object is the provision of a simple locking means for pivoted members which includes a locking arm having a fulcrum at one end movable along an elongate path on one of said levers or handles and having its other end slidable in a guide member fixed on an opposed member such as a handle or lever.

Other objects and advantages of this invention will become more apparent as the following description of two embodiments thereof progresses, reference being made to the accompanying drawing in which like reference characters are employed to designate like parts throughout the same.

In the drawings:

Figure 1 is a plan view of a device embodying my invention and shown as applied to a pair of opposed handles or levers, such as a pair of pliers;

Figure 2 is a view similar to that shown in Figure 1 illustrating the adjustment of the clamping means to grip a workpiece in the jaws of the pliers;

Figure 3 is a section taken on line 33 of Fig. 2;

Figure 4 is a section taken on the line 44 of Fig. 2;

Figure 5 illustrates a modified form of the invention which is further simplified in construction and is shown as applied to a pair of pliers or similar tool; and

Figure 6 is a section taken on the line 66 of Figure 5.

In carrying out my invention, I have illustrated the same as applied to a clamping tool, such as a pair of pliers or the like for clamping the handles thereof in a predetermined relative position, although it is to be understood that the invention is not to be limited in this respect, since it is equally applicable to other types of levers, handles, cranks, clamps or the like.

Referring now more particularly to Figs. 1 to 4, inclusive, in which I have illustrated one form of the invention as applied to the opposed handles or levers of a tool such as pliers for locking the same in a predetermined relative position for gripping a workpiece, the tool is indicated as comprising a pair of crossed handles 1 and 2, respectively, pivotally connected at 3 and terminating in work-gripping jaws 4 and 5, respectively. The jaw 5 may be provided with a projection 6 which is movable in the path of a fixed lug 7 on the jaw 4 to limit the spread of the jaws or handles. In the opposite direction. of course, the jaws may move freely 2,701,487 Patented Feb. 8, 1955 "ice vention is very apparent from the drawings illustrating the application of the same. The handle 2 of the jaw 5 is provided with an integral offset portion 8 which extends rearwardly of the handle from a point beyond the fulcrum 3 and preferably extends outwardly of the handle and having at least a portion thereof in the plane of the handles 1 and 2. This outwardly extending portion may be termed a segment which is provided with an elongate slot 9 preferably in arcuate or curved form and whose radii preferably converge to a location between the handles 1 and 2 and rearwardly with respect to a guide member carried by the opposed handle or lever 1.

The handle 1 is provided at a point opposite the offset portion 8 with a fixed guide member 10 which, in the form illustrated in Figs. 1 through 4, is a U-shaped straplike member rigidly fixed to the handle 1 or formed integral therewith to provide a flat elongate slot or opening through which a clamping member 11 is adapted to pass.

The clamping member 11 preferably comprises a fiat rigid strip having a width less than the length of the fiat opening through which the member passes in the guide 10 and is provided at one end with a stud 12 which is disposed at right angles to the arm 11 and through the slot 9 in which it is free to slide at the will of the operator either to adjust the clamping arm 11 toward a locking position or to release it therefrom. A washer 13 is provided on the shank of the stud and engages the upper surface of the offset portion 8 as viewed in Fig. 3. A nut 14 may be threaded onto the threaded end of the stud to assemble the locking member 11 in operative relation to the offset portion 8 and the slot 9. It is understood that the stud and the locking member 11 under certain conditions have freedom of movement along the slot 9 to and from a locking position but by virtue of the construction of the device is adapted to lockingly engage a wall of the slot under load gripping or locking conditions which will be explained more fully hereinafter.

It will be noted that if an imaginary straight line 9' is projected from any of the points of bearing of the stud 12 along a wall or edge of the elongate slot 9 in handle 2 to the fulcrum or center on which the handles and respective jaws are pivoted, and if an imaginary line 10 is projected from the bearing or binding points 10 and 10 of the inverted U-shaped guide member 10 toward the jaw end of the handle 1 and which points are engaged by the opposite longitudinal edges of the arm 11, these imaginary lines will intersect at a point remote from the fulcrum 3 of the handles and behind the jaws 4 and 5. This is clearly indicated in Figs. 1 and 2.

It will also be noted that by virtue of the construction disclosed a positive locking action is available for any position of the jaws 4 and 5 in gripping an object, it being merely necessary to grip the workpiece as illustrated in Fig. 2 at W between the jaws by compressing the handles 1 and 2 toward each other and then shifting the locking arm 11 from a position such as is shown in Fig. 1 to the position shown in Fig. 2. In so shifting this member, the stud 12 may be pushed along the elongate slot 9 by applying a slight thumb or finger pressure against the stud 12 and pushing the locking member 11 to the position shown in Fig. 2. During movement of the locking member 11 from one position to the other, its free end will freely slide through the flat elongate opening 10 provided by the inverted U-shaped fixed guide member 10 and the adjacent wall of the handle 1 to which it is attached. When the locking arm 11 is in locking position as in Fig. 2 to clamp a workpiece in the pliers, a positive binding or gripping condition is established between the longitudinal side edges of the locking arm 11 and the respective legs of the inverted U-shaped fixed member 10 on the handle 1, and also between the stud 12 and the walls of the curved slot 9.

If the thickness of the workpiece W is more or less than that indicated, the locking arm can be shifted along the slot 9 and within the elongate opening 10' to estab- Iish the same eifective binding and locking effect to maintain the handles 1 and 2 and consequently the jaws 4 and 5 in clamping position upon the workpiece W. Since neither a projection of the slot 9 toward the jaws nor the longitudinal axis of the fixed clamping member 10 passes through the fulcrum 3, but lie in a position remote therefrom, an elfective wide range of easily established and easily disposed of locking adjustments are available without the use of springs or other tensioning means intended to exert a normal pressure on the clamping arm 11. It will be noted that although the imaginary line 9' passes through the axis of the fulcrum 3, it will always be intersected by the line 10 at a point behind the fulcrum 3, that is, on the handle side thereof. It will be understood that work pieces of different thicknesses may be clamped between the jaws 4 and 5 within their pivotal limits. In each instance, however, the clamping relationship between the fixed guide 10, the slot 9 and the respective portions of the locking member 11 engaged thereby will be substantially the same, that is, the imaginiary lines 9 and 10" when projected forwardly toward the jaws will converge and intersect at a point behind the fulcrum 3 and the jaws 4 and 5.

Referring now to Figs. 5 and 6, I have illustrated a further simplified form of the invention. In this instance, I have illustrated the same as also applied to a pair of pliers or similar tool but have eliminated the slotted portion of one of the jaw handles and have so modified the clamping member that, while it is as effective in operation as the form of the invention illustrated and described above, it is of considerably simplified construction, easy to assemble and can be produced at low cost. In this form of the invention, the handle 2 is of itself formed with a portion bowed outwardly in the plane of the pliers as at 20. This portion of the handle in cross section is flat and is adapted to receive thereover the formed enveloping end of the clamping member 21 in slidable relation thereto. One end of the clamping member 21 is slidable between guiding members or lugs 22 spaced apart on a fiat portion of the handle 1 and in offset relation to each other. The opposite end of the clamping member 21 is formed to envelope the arcuate portion of the handle 2 to permit sufficient clearance for the clamping member to slide over this portion of the handle when desired and also to provide means whereby the handle 2 may be gripped by the clamping member under load-gripping conditions. A finger grip 23 is formed integral with the enveloping end of the clamping member 21 and extends outwardly along the longitudinal axis of the member by means of which the operator may, by applying thumb or finger pressure to the portion 23, urge the same toward the left in Fig. 5 into clamping position when a workpiece is to be clamped between the jaws 4 and 5. That portion of the enveloping end of the clamping member 21 which overlies the top of handle 2 is indicated at 24 and terminates in a projection 25 which is bent inwardly toward the main body of the clamping member 21 and which engages the inner arcuate edge of the bowed or arcuate portion of the handle 2 to cooperate with the end wall 26 of the member 21 engaging the outer edge of the bowed portion 20 thereby to guide the clamping member in its movement along the bowed portion and to keep it in alignment with the opposed handle 1 as the opposite end thereof operates between the lugs 22.

From the above it will be noted that the relationship between the locking member 21, the operative portion of the bowed part 20 of the handle 2 and the guiding members or lugs 22, is substantially the same as that existing between the clamping member 11, the arcuate guide slot 9 and the fixed guide member 10, respectively.

Here again, as in the embodiment shown in Figs. 1 through 4, it will be noted that an imaginary line 30 extending from any one of the points of bearing of the enveloping end of the arm 21 and along the curved upper wall 20 of the handle 2 and passing through the fulcrum 3 will be intersected by an imaginary line extending from the binding or bearing points 30 and 30" between the opposite longitudinal edges of the arm 21 and the respective lugs 22, such point of intersection also being behind the fulcrum 3 and on the handle side thereof.

The operation of this embodiment of the invention is in principle the same as that disclosed in Figs. 1 through 4, the effective binding or gripping points being defined as between the respective longitudinal edges 27 of the arm 21 and the adjacent respective lugs 22, as Well as between the enveloping end of the arm 21 and the curved edges of the portion 20 of the handle 2, It is pointed out that in this form of the invention it is equally unnecessary to employ the use of springs or other tensioning devices thereby contributing to the simplicity and low cost of the device. As is the case with the first embodiment described above, the center about which the curved portion 20 is formed is located at a point remote from the fulcrum 3. Furthermore, it will be clear that there is provided in both forms of the invention, as illustrated herein, what might be termed a binding area restricted to a location behind the fulcrum 3 and the pivoted members 4 and 5.

Various changes may be made in the details of construction and arrangement of parts of the invention without departing from the spirit thereof or the scope of the appended claims.

I claim:

1. In a device comprising pivotally opposed members, means for locking or holding said opposed members in a preselected position, said means comprising guide means on each of said members, and a locking member operatively connected with and movable along each of said guide means, one end of said locking member having pivotal and sliding support along one of said guide means, each of said guide means extending toward a common point located behind the fulcrum of said pivoted members.

2. In a device comprising pivotally opposed members, means locking or holding said opposed members in a selected position, said means comprising guide means on each of said members, a locking arm bridging said members and frictionally engageable with said guiding means to lock the members in a fixed relative position, said guide means on one of the members slidably receiving said locking arm having a portion at one of its ends for guiding movement therealong, and guide means on said other member comprising an inverted U-shaped portion forming with said other member an opening for slidably receiving the other end of said locking arm, each of said guide means extending toward a common point located behind the fulcrum of said pivoted members.

3. In a device comprising pivotally opposed members, means for locking and holding said members in a selected position, said means comprising a link bridging said members, one of said members having a portion formed with an arcuate guide slot, means on one end of said link projecting transversely thereof and disposed in said slot to slidably connect said link for movement along said slot, and an elongate guide formed on said other opposed member for slidably receiving the other end of said link, the end walls of said last named guide being engageable with opposed edges of said link in frictional binding relation, said arcuate slot and said elongate guide extending toward a common point behind the fulcrum of the pivoted members.

4. A device of the class described comprising a pair of opposed relatively pivoted members and means for frictionally holding said members in a predetermined relative position, said means comprising a link connecting said members, one end of said link being formed to envelop a portion of one of said members and movable longitudinally of said member portion, and means on the other member for receiving the other end of said link in slidable relation thereto for guiding said link transversely of said other member upon relative movement of said members, said guiding means having engagement with opposite sides of said link, the engagement of the guiding means on opposite sides of said link and the engagement of the enveloping end of said link with said one member portion defining a three point binding means located behind the fulcrum of the pivoted members.

5. In a device of the class described, a pair of pivoted opposed relatively movable members, one of said members having an intermediate portion formed out of its general contour, a guide means on said other member and a link connecting said members, one end of said link being slidable longitudinally in said guide means, the other end of said link embracing and being slidable along the portion of said first member formed out of said first members general contour, the respective end portions of the link having binding engagement with the guide means and the said intermediate portion of one of said pivotally opposed members to lock said opposed pivoted members in pre-selected relative positions, said intermediate portion members.

References Cited in the file of this patent UNITED STATES PATENTS Hubbell Jan. 29, 1889 6 Islin Mar. 10, 1891 Tinsman et a1 Aug. 18, 1896 Ingram Aug. 3, 1915 Reede Aug. 11, 1931 Davis Nov. 23, 1948 

